1. Field of the Invention
The present invention relates to wireless localization in a multi-story environment, and more particularly, to an apparatus for determining an indoor location and a method for determining an indoor location in a multi-story building.
2. Description of the Related Art
In recent years, urbanization has been rapidly progressed in each country, and many high-rise buildings have been constructed in a center of town. For this reason, when locational information of a target is needed in a three-dimensional multi-story building, locational information of simple two-dimensional plane coordinates is not useful for estimating a precise location of the target. Thus, an overriding problem to be solved for wireless localization in the multi-story building is to accurately determine a floor of the building at which a user is positioned. Particularly, in order to provide various application services for indoor localization, there is an increasing need for floor information, and a technology for determining an inter-floor location has been increasingly noticed due to the need for indoor localization.
Indoor wireless localization depends on a GPS (Global Positioning System) having an accuracy of 1 m to 10 m. The GPS is developed for military purpose, but has widely used for civilian purpose such as weapon guiding, navigation, measurement, cartography, land surveying, and visual synchronization in addition to the military purpose. In this way, the GPS exhibits an optimal localization performance in an outdoor environment, but is not used in an indoor environment due to signal attenuation and dispersion. That is, it is necessary to apply requirements different from an outdoor localization system to an indoor localization system. Many technologies for indoor localization have been suggested over the last ten years. Among these technologies, a technology using Wi-Fi that has been already commercialized and is relatively low-cost has been researched. A Wi-Fi hotspot is widely used in buildings of town, and since most terminals such as a smartphone, a tablet PC, and a laptop computer have a Wi-Fi available function, it is possible to perform inter-floor localization using a Wi-Fi signal.
Further, various algorithms that perform wireless localization such TOA (Time of Arrival), AOA (Angle of Arrival), and RSS (Received Signal Strength) by using a Wi-Fi signal as in a technology for GPS-based outdoor wireless localization have been proposed. Particularly, since the AOA and TOA techniques need to measure an angle and perform time synchronization, additional devices are required. However, since the RSS technique needs to simply measure magnitude of a signal, it is possible to provide locational information at low implementing cost.
The related art of the present invention is described in Korean Patent Publication No. 2012-0069267 (Jun. 28, 2012).